IT IS UNCONVENTIONAL and INNOVATIVE. This is a vest type Child Restraint System and uses a revolutionary technology to increase safety for the little traveler by optimizing the adult seat belt fit for their body. IT IS SAFE AND LEGAL. This is certified for use in motor vehicles, meets or exceeds all applicable FMVSS 213 requirements so is legal to use in all US states. IT IS COMPACT, ULTRA-LIGHTWEIGHT, AND PORTABLE. This is perfect for a family travel, fits 3-children in the same row of a vehicle with comfort and ease; ridesharing, taxi, or rental car. Great for grandparents and caregivers because it’s lightweight and easy to install and use. IT CAN BE USED WITH OR WITHOUT TETHER. This is to use with a vehicle lap belt and top tether by securing the vest with a top tether anchor in the vehicle. Also, this can be used with a lap and shoulder belt only without a tether strap. WHO CAN USE IT? The X-Large size is recommended to use 3 years and above and a weight between 80 lbs. and 110 lbs.